The prior-art shuttle valve is a one way valve, as described in the "Hydraulic and Pneumatic handbook" (edited by Hydraulic and Pneumatic association of Japan, translated by "Hydraulic and Pneumatic Handbook" translator group, Published by Machinery Industry Publishing House of China, November 1984, P.330) and "Hydraulic Technology handbook-Revised New Edition" (edited by Hydraulic Technology handbook Editorial Committee of Japan, Published by Japan Periodical Industrial News Agency, in the year 1976, P. 1163) (FIGS. 1, 2). The prior-art shuttle valve comprises a shell (2), a steel ball (11) and a shuttle chamber (29) within the central part of the shell, the two ends of the shuttle chamber are connected respectively with the two fluid openings (22) and (22'), and the middle part of the shuttle chamber is connectd with a fluid outlet (21); the steel ball is placed within the shuttle chamber of the shell, it can be moved by the pressurized fluid entering from the fluid opening (22) or (22'), it automatically seals off the fluid opening at the lower pressure side, preventing the fluid from entering the valve from this side, thereby lets the higher pressure fluid flow through the shuttle chamber to the fluid outlet (21). This kind of shuttle valve is capable of selecting the fluid access automatically with respect to the fluid pressure, i.e. automatically seals off one fluid access and connects with the other. It has the function of an automatic alternating non-return valve. But with this kind of shuttle valve the fluid passing through it can not flow reversely, and the flow-rate of the fluid can not be regulated.